Search

The presence of pathogens and the state of diseases, particularly skin diseases, may alter the composition of human skin microbiome. HIV infection has been reported to impair gut microbiome that leads to severe consequences. However, with cutaneous manifestations, that can be life-threatening, due to the opportunistic pathogens, little is known whether HIV infection might influence the skin microbiome and affect the skin homeostasis. This study catalogued the profile of skin microbiome of healthy Cameroonians, at three different skin sites, and compared them to the HIV-infected individuals. Taking advantage on the use of molecular assay coupled with next-generation sequencing, this study revealed that alpha-diversity of the skin microbiome was higher and beta-diversity was altered significantly in the HIV-infected Cameroonians than in the healthy ones. The relative abundance of skin microbes such as Micrococcus and Kocuria species was higher and Cutibacterium species was significantly lower in HIV-infected people, indicating an early change in the human skin microbiome in response to the HIV infection. This phenotypical shift was not related to the number of CD4 T cell count thus the cause remains to be identified. Overall, these data may offer an important lead on the role of skin microbiome in the determination of cutaneous disease state and the discovery of safe pharmacological preparations to treat microbial-related skin disorders., Competing Interests: KO belongs to the Department of Bio-engineering Nursing, which was funded by Saraya Co., Ltd. Osaka, Japan, from April 1, 2023. The funder was not involved in any stage of this study, and thus does not constitute any conflict of interest on this study. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Ogai, Nana, Lloyd, Arios, Jiyarom, Awanakam, Esemu, Hori, Matsuoka, Nainu, Megnekou, Leke, Ekali, Okamoto and Kuraishi.)

Background: Human Herpesvirus-8 (HHV-8) is the etiologic agent of Kaposi's sarcoma (KS), a multicentric angio-proliferative cancer commonly associated with Human Immunodeficiency Virus (HIV) infection. KS pathogenesis is a multifactorial condition hinged on immune dysfunction yet the mechanisms underlying the risk of developing KS in HHV-8 seropositive adults remains unclear. Here we explored whether soluble markers of HIV-1-related systemic immune activation (SIA) and angiogenesis (VEGF and FGF acidic) are involved in the pathogenesis of KS in adults with HHV8., Methodology: Blood samples from 99 HIV-1 infected and 60 HIV-1 uninfected adults were collected in Yaoundé, Cameroon. CD3+/CD4+ T cell counts and HIV-1 plasma viral load were determined using the Pima Analyzer and the RT-PCR technique, respectively. Plasma levels of SIA biomarkers (sCD163, sCD25/IL-2Rα, and sCD40/TNFRSF5) and biomarkers of progression to KS (VEGF and FGF acidic) were measured using the Luminex assay. Seropositivity (IgG) for HHV-8 was determined using the ELISA method., Results: Overall, 20.2% (20/99) of HIV-1 infected and 20% (12/60) of HIV-1 uninfected participants were seropositive for HHV8. Levels of sCD163, sCD25/IL-2Rα, sCD40/TNFRSF5, and FGF acidic were higher in the HIV-1 and HHV8 co-infection groups compared to the HIV-1 and HHV8 uninfected groups (all P <0.05). In addition, Higher plasma levels of VEGF correlated with sCD163 (r s = 0.58, P =0.0067) and sCD40/TNFRSF5 (r s = 0.59, P = 0.0064), while FGF acidic levels correlated with sCD40/TNFRSF5 (r s = 0.51, P = 0.022) in co-infected. In HIV-1 mono-infected donors, VEGF and FGF acidic levels correlated with sCD163 (r s =0.25, P = 0.03 and r s = 0.30, P = 0.006 respectively), sCD25/IL-2Rα (r s = 0.5, P <0.0001 and r s = 0.55, P <0.0001 respectively) and sCD40/TNFRSF5 (r s = 0.7, P <0.0001 and r s = 0.59, P <0.0001 respectively) and even in patients that were virally suppressed sCD25/IL-2Rα (r s = 0.39, P = 0.012 and r s = 0.53, P = 0.0004 respectively) and sCD40/TNFRSF5 (r s = 0.81, P <0.0001 and r s = 0.44, P = 0.0045 respectively)., Conclusion: Our findings suggest that although the development of KS in PLWH is multifactorial, HIV-associated SIA might be among the key drivers in coinfections with HHV8 and is independent of the patients' viremic status., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Nana, Esemu, Besong, Atchombat, Ogai, Sobgui, Nana, Seumko’o, Awanakan, Ekali, Leke, Okamoto, Ndhlovu and Megnekou.)

The commensal microbes of the skin have a significant impact on dermal physiology and pathophysiology. Racial and geographical differences in the skin microbiome are suggested and may play a role in the sensitivity to dermatological disorders, including infectious diseases. However, little is known about the skin microbiome profiles of people living in Central Africa, where severe tropical infectious diseases impose a burden on the inhabitants. This study provided the skin profiles of healthy Cameroonians in different body sites and compared them to healthy Japanese participants. The skin microbiome of Cameroonians was distinguishable from that of Japanese in all skin sites examined in this study. For example, Micrococcus was predominantly found in skin samples of Cameroonians but mostly absent in Japanese skin samples. Instead, the relative abundance of Cutibacterium species was significantly higher in healthy Japanese. Principal coordinate analysis of beta diversity showed that the skin microbiome of Cameroonians formed different clusters from Japanese, suggesting a substantial difference in the microbiome profiles between participants of both countries. In addition, the alpha diversity in skin microbes was higher in Cameroonians than Japanese participants. These data may offer insights into the determinant factors responsible for the distinctness of the skin microbiome of people living in Central Africa and Asia., (© 2022. The Author(s).)

Characterization of microbial communities in the skin in healthy individuals and diseased patients holds valuable information for understanding pathogenesis of skin diseases and as a source for developing novel therapies. Notably, resources regarding skin microbiome are limited in developing countries where skin disorders from infectious diseases are extremely common. A simple method for sample collection and processing for skin microbiome studies in such countries is crucial. The aim of this study is to confirm the feasibility of collecting skin microbiota from individuals in Yaoundé, a capital city of Cameroon, and subsequent extraction of bacterial DNA in a resource limited setting. Skin swabs from several individuals in Yaoundé were successfully obtained, and sufficient amount of bacterial 16S ribosomal RNA-coding DNA was collected, which was confirmed by quantitative PCR. The median copy number of 16S ribosomal RNA gene varied across participants and collection sites, with significantly more copies in samples collected from the forehead compared to the left and right forearm, or back. This study demonstrated that collecting surface skin microbes using our swabbing method is feasible in a developing country. We further showed that even with limited resources, we could collect sufficient amount of skin microbiota from the inhabitants in Yaoundé where no studies of skin microbiome were reported, which can be passed to further metagenomic analysis such as next generation sequencing.